Zonglin He1,2, Huailiang Wu1,2, Siyu Zhang1,2, Yuchen Lin1,2, Rui Li1,2, Lijie Xie1,2, Zibo Li1,2, Weiwei Sun1,2, Xinyu Huang1,2, Casper J P Zhang3, Wai-Kit Ming1,2,4,5. 1. Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, Guangzhou, Guangdong, China. 2. Faculty of Medicine, International School, Jinan University, Guangzhou, Guangdong, China. 3. School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. 4. School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. 5. Harvard Medical School, Harvard University, Boston, Massachusetts.
Abstract
BACKGROUND: Secondhand smoke (SHS) exposure can trigger asthma exacerbations in children. Different studies have linked increased asthma symptoms and even deaths in children with SHS, but the risk has not been quantified uniformly across studies. We aimed to investigate the role of SHS exposure as a risk factor of asthma among children. METHODS: We performed a systematic review in PubMed, Scopus, and Google Scholar from June 1975 to 10 March 2020. We included cohort, case-control, and cross-sectional studies reporting odds ratio (OR) or relative risk estimates and confidence intervals of all types of SHS exposure and childhood asthma. RESULTS: Of the 26 970 studies identified, we included 93 eligible studies (42 cross-sectional, 41 cohort, and 10 case-control) in the meta-analysis. There were significantly positive associations between SHS exposure and doctor-diagnosed asthma (OR = 1.24; 95% confidence interval (CI) = 1.20-1.28), wheezing (OR = 1.27; 95% CI = 1.23-1.32) and asthma-like syndrome (OR = 1.34; 95% CI = 1.34-1.64). The funnel plots of all three outcomes skewed to the right, indicating that the studies generally favor a positive association of the disease with tobacco exposure. Subgroup analysis demonstrated that younger children tended to suffer more from developing doctor-diagnosed asthma, but older children (adolescents) suffered more from wheezing. There was no evidence of significant publication or small study bias using Egger's and Begg's tests. CONCLUSION: The results show a positive association between prenatal and postnatal secondhand smoking exposure and the occurrence of childhood asthma, asthma-like syndrome, and wheezing. These results lend support to continued efforts to reduce childhood exposure to secondhand smoke.
BACKGROUND: Secondhand smoke (SHS) exposure can trigger asthma exacerbations in children. Different studies have linked increased asthma symptoms and even deaths in children with SHS, but the risk has not been quantified uniformly across studies. We aimed to investigate the role of SHS exposure as a risk factor of asthma among children. METHODS: We performed a systematic review in PubMed, Scopus, and Google Scholar from June 1975 to 10 March 2020. We included cohort, case-control, and cross-sectional studies reporting odds ratio (OR) or relative risk estimates and confidence intervals of all types of SHS exposure and childhood asthma. RESULTS: Of the 26 970 studies identified, we included 93 eligible studies (42 cross-sectional, 41 cohort, and 10 case-control) in the meta-analysis. There were significantly positive associations between SHS exposure and doctor-diagnosed asthma (OR = 1.24; 95% confidence interval (CI) = 1.20-1.28), wheezing (OR = 1.27; 95% CI = 1.23-1.32) and asthma-like syndrome (OR = 1.34; 95% CI = 1.34-1.64). The funnel plots of all three outcomes skewed to the right, indicating that the studies generally favor a positive association of the disease with tobacco exposure. Subgroup analysis demonstrated that younger children tended to suffer more from developing doctor-diagnosed asthma, but older children (adolescents) suffered more from wheezing. There was no evidence of significant publication or small study bias using Egger's and Begg's tests. CONCLUSION: The results show a positive association between prenatal and postnatal secondhand smoking exposure and the occurrence of childhood asthma, asthma-like syndrome, and wheezing. These results lend support to continued efforts to reduce childhood exposure to secondhand smoke.
Authors: Jocelyn M Biagini; John W Kroner; Asel Baatyrbek Kyzy; Alexandra Gonzales; Hua He; Mariana Stevens; Brittany Grashel; Daniel Spagna; Samuel Paul; Rahul Patel; Angelo Bucci; Michael G Sherenian; Liza Bronner Murrison; Lisa J Martin; Gurjit K Khurana Hershey Journal: J Allergy Clin Immunol Date: 2021-10-18 Impact factor: 14.290
Authors: David Rojas-Rueda; Emily Morales-Zamora; Wael Abdullah Alsufyani; Christopher H Herbst; Salem M AlBalawi; Reem Alsukait; Mashael Alomran Journal: Int J Environ Res Public Health Date: 2021-01-15 Impact factor: 3.390
Authors: Hamed Janbazacyabar; Jeroen van Bergenhenegouwen; Johan Garssen; Thea Leusink-Muis; Ingrid van Ark; Marthe T van Daal; Gert Folkerts; Saskia Braber Journal: Front Immunol Date: 2021-12-23 Impact factor: 7.561
Authors: Elisabet Johansson; Lisa J Martin; Hua He; Xiaoting Chen; Matthew T Weirauch; John W Kroner; Gurjit K Khurana Hershey; Jocelyn M Biagini Journal: Clin Exp Allergy Date: 2021-02-13 Impact factor: 5.401